Objective testing methods and means for the clinical diagnosis of Raynaud's Phenomenon of occupational origin (vibration-induced white finger disease) and for assessing patient disability arising from long-term usage of hand-held vibrating tools are at present inadequate. Peripheral blood flow measurements utilizing plethysmographic and ultrasonic techniques have been used (see Zweifler, "Detection of Occlusive Arterial Disease in the Hand and its Relevance to Occupational Hand Disease," Proceedings of the International Occupational Hand-Arm Vibration Conference, pp 12-17 DHEW (NIOSH) Publication No. 77-110, Cincinnati, Apr. 1977, and Laroche, "Traumatic Vasospastic Disease in Chain-Saw Operators," Can. Med. Assoc. J., 115:1217, 1976). To detect changes in the peripheral nervous system, the depth-sense and the two-point discrimination aesthesiometers were developed by Renfrew (see Renfrew, "Aesthesiometers," The Lancet, 1:1011, 1960, and Renfrew, "Fingertip Sensation. A Routine Neurological Test," The Lancet, 1:396, 1969). Both instruments have been used in a survey of pedestal grinders (see Pelmear, Taylor and Pearson, "Raynaud's Phenomenon in Pedestal Grinders," in The Vibration Syndrome, W. Taylor, London: Academic Press, Inc., 1974, pp 141-147), and the results show a loss in fingertip sensation. Mackworth (Mackworth, "Finger Numbness in Very Cold Winds," J. Appl. Physiol., 5:533-543, 1952-53) used a two-point discrimination instrument in assessing finger numbness when exposed to cold environments.
As above mentioned, previously used testing devices for assessing loss of fingertip sensory perception have been unsatisfactory and inadequate because they are relatively complicated, expensive and difficult to use. There is a substantial need for testing instruments with improved sensitivity, reliability and versatility, and which are simpler to use than the previously employed devices.